1. Field of the Invention
The present invention relates to brilliant cut gemstones, particularly brilliant cut diamonds. The diamond includes a crown and a pavilion separated by a girdle. The diamond has a particular general shape and the surface of the diamond is cut into brilliant facets the geometric shape of which maintain the particular general shape of the diamond.
2. Prior Art
Gemstones are generally cut with facets forming the exterior surface of the stone. The surface of the facets are then polished to obtain the brilliance, dispersion and/or scintillation desired from the gem. Facets cut in a gemstone may also form a geometric figure or design. The prior art is replete with teachings making gems from gemstones by cutting facets in the surface of the stone and then polishing the surface of the facet to obtain the brilliance and scintillation desired, when the gem is exposed to light. Facets are usually cut in the crown and in the pavilion of the stone.
An example of some prior art utility patents that teach crown facets and pavilion facets on a gemstone include:
The patent to Schenck (U.S. Pat. No. 809,531) teaches forming an eight (8) sided, octagon, table on the crown of a stone with crown facets having circular edges defining the upper edge of the girdle of the stone, between the crown and the pavilion. Pavilion facets adjacent the girdle also have circular edges defining the lower edge of the girdle. The facets cut in the stone are for providing brilliance. The patent to Heller (U.S. Pat. No. 1,291,506) teaches cutting facets in a gemstone so that all the pavilion facets are cut and polished to provide brilliance to the stone. The crown has a six (6) hexagon table with a blend of bright facets and dull facets around the polished table of the crown. The patent to Huisman, et al (U.S. Pat. No. 3,585,764) the cutting of a stone to produce 72 pavilion facets, polishing the girdle to a 90 degree edge and cutting 38 facets in the girdle. The patent to Grossbard (U.S. Pat. No. 4,118,949) teaches a step cut diamond in generally rectangular or emerald cut shape. The crown has a generally rectangular table with a series of trapezoid cut facets defining the girdle of the stone. The patent to Polakiewicz (U.S. Pat. No. 3,763,665) teaches cutting a gemstone so that the crown is in geometric parts. An octagonal table is defined on the crown by a plurality of trapezoidal facets, with each trapezoid facet having an edge common to a triangular facet. The pavilion of the stone is fully faceted in identical cut quadrants. The patent to Cheng (U.S. Pat. No. 6,305,193 B1) teaches a gemstone cut with an octagon shaped table with facets extending from the table to a girdle extending around the circular stone. The patent to Johnston (U.S. Pat. No. 5,072,549) teaches a method of cutting a gemstone to form a pentagonal shaped gem. The facets produce a five (5) pointed star in the crown of the stone.
It will be noticed that none of these prior art patents teach cutting facets into a gemstone to make the gemstone a brilliant gem where the gem is in the form of a geometric pattern and the facets together, form the same geometric pattern of the gem.
An example of some prior art design patents that show crown and pavilion facets cut on a gemstone are:
The design patents to Schachter (U.S. Pat. No. 340,670) and d""Haene (U.S. Pat. No. 348,024) each show a stone which has an eight (8) sided, octagon table defined on the crown with the stone in a generally octagon configuration. The pavilion of the stone has facets that do not maintain the octagon configuration of the stone. The design patents to Akselrod (U.S. Pat. No. 333,108) and Akselrod (U.S. Pat. No. 327,412) and to Ishida (U.S. Pat. No. 287,232) each show a gemstone with an eight (8) sided, octagon shaped table on the crown of a generally round shaped stone. The facets cut in the pavilion of the stone do not carry out the general shape of the stone, which is round, nor the geometric design of the table on the crown, which is octagon. The design patents to Alvarado (U.S. Pat. No. 411,133) and to Bodner (U.S. Pat. No. 217,634) each show a stone cut with an hexagon table design in the crown. Alvarado shows a stone with a generally hexagon shape. Bodner shows a circular shaped, round stone. Each design shows facets cut in the pavilion of the respective stone but neither stone carries the shape of the stone in the design cut in the pavilion. The design patent to Gennari (U.S. Pat. No. 273,372) shown a tear drop shaped stone with a floral design formed by the facets. The design patent to Fine (U.S. Pat. No. 141,259) shows a gemstone with a round configuration with a ten (10) sided table defined by the facets cut in the crown.
It will be noticed further that none of the design patents show a stone with a common geometric signature carried throughout the cuts in the stone.
The present invention provides a gemstone, such as a diamond, for example, cut into a gem having a geometric configuration, when viewed from the top of the stone. Facets cut in the crown of the stone provide a table on the crown which is directly related to the geometric configuration or signature of the stone. Triangular facets cut in the crown, with each triangle having a leg that is common with an edge of the table in the crown, define a second geometric figure in the crown which is directly related to the signature of the stone and to the configuration of the table in the crown. A plurality of trapezoid shaped facets are cut in the crown, the ends of which abut each other defining the perimeter of the stone. The width of each trapezoid facet is a minor fraction of the distance between the virtual center of the crown and the girdle of the stone. The signature of the stone is high lighted by the trapezoid shape facets which also frame the second geometric figure and the table cut in the crown.
The girdle, following the signature of the stone, separates the crown from the pavilion of the stone. A plurality of trapezoid shaped facets are cut in the pavilion, each trapezoid facet extending from the apex of the pavilion toward the girdle of the stone. Each trapezoid facet falls uniformly short of the girdle of the stone. The trapezoid facets form a sharp geometric figure in the pavilion that is related in both position and configuration to the signature of the stone and to the geometric figure in the crown of the stone. The sharpness of the geometric figure cut in the pavilion is softened by pairs of triangular cut facets. Each softening triangular facet has one leg common with a leg of a trapezoid, one leg common with the leg of an adjacent softening triangle and one free leg. A plurality of generally pentagon facets separate the softened geometric figure cut in the pavilion from the girdle of the stone. The width of each pentagon shaped facet that is parallel to the shortest line between the apex of the pavilion and the girdle of the stone is a minor fraction of the shortest distance between the apex of the pavilion and the girdle separating the crown from the pavilion.
From another aspect the present invention provides a gemstone, for example, a diamond cut into a gem having a hexagon configuration. Facets cut into the crown of the stone provide a table in the crown which is directly related to and offset from the hexagon configuration, which is the signature of the stone. Triangular shaped facets, cut in the crown, define a hexagram which is directly related to the hexagon table cut in the crown. A plurality of trapezoid facets, each abutting an adjacent trapezoid in the plurality and at a point of the hexagram, define the perimeter of the crown of the stone. The width of each trapezoid is a minor fraction of the distance between the virtual center of the crown and the girdle of the stone. The signature of the stone is high lighted by the trapezoid cut facets.
A set of six (6) trapezoid shaped facets are cut into the pavilion of the stone, each trapezoid facet of the six (6) facets extending from the apex of the pavilion toward the girdle and defining a sharp six (6) pointed star. Six (6) pair of triangle shaped facets are cut in the pavilion with each pair of triangle facets having a common leg and each triangle facet having one leg common with a leg of a trapezoid, soften the sharp six (6) pointed star, the center of which is the apex of the pavilion. Both the geometrical configuration and the position of the six (6) pointed star are related to the signature of the stone and the hexagram in the crown. A set of six (6) pentagon facets, each extending from the girdle of the stone toward the apex of the stone make contact with the softened six (6) pointed star. The width of each pentagon facet that is parallel to the shortest line between the apex of the pavilion and the girdle of the stone is a minor fraction of the distance between the apex of the pavilion and the girdle of the stone.